DESCRIPTION (provided by application): The history and philosophy of cell biology is largely unexplored in comparison to that of molecular biology. Of the two recent books that have examined the origins of cell biology, Bechtel's Discovering Cell Mechanisms (2006) only followed advances prior to 1970 while Rasmussen's Picture Control (1997) limited itself to a description of the development of biological electron microscopy until 1960. This application requests funds to write a history of cell biology focused on the research that elucidated the secretory pathway, primarily conducted at the Rockefeller University. In particular, the book will use the year 1975 as a pivot point to examine and describe the development of the signal hypothesis by G[unreadable]nter Blobel and David Sabatini prior to 1975, its demonstration by Blobel in 1975, and his extension and elaboration of it into a model of protein topogenesis in subsequent years (Aim 1). The book will, in addition, explore the philosophical relationships between molecular biology and cell biology, and will argue that, of the two disciplines, cell biology is more capable of explaining biological phenomena than the extreme reductionist research program of molecular biology (Aim 2)